I've dissected my Profoto Pro B2 battery a few times to swap batteries and it got me thinking..it is possible to create a lithium polymer battery replacement in the casing? it will take up a lot less space (can pad the excess space inside to reduce jiggles of course) and will be lighter.

I'm not too familiar with how the difference in lead acid voltage (12V) vs lithium polymer pack voltage (11.1v -14.8v?) will affect the performance, or if it's even safe?

I believe hensel already has a lithium polymer solution...I wonder if anyone has taken a look at that?

Yes they have. I expect that you would need a different charger if you did this. Sorry, can't answer about the safety of a direct replacement.

I'd like to find cheap large Li+ batteries to replace the lead acid batteries which power my pure sinewave inverter.

I don't think you even need a pure sinewave inverter?what are you powering. I used to use a similar solution, got a lithium polymer solution and my lead acid batteries and inverter's gathering dust now.

yes a different charger definitely...will raise this possibility with someone with more battery experience to explore the possibility

hi shermanthe 7B battery consists of some sort of circuit board heavily soldered to the contacts of a lead acid battery. you just need to desolder the contacts, replace the battery, resolder. piece of cake. send it to some wiring guy to do the soldering for you, shouldn't cost you more than a few bucks or so for his time.

the 7B battery consists of some sort of circuit board heavily soldered to the contacts of a lead acid battery. you just need to desolder the contacts, replace the battery, resolder. piece of cake. send it to some wiring guy to do the soldering for you, shouldn't cost you more than a few bucks or so for his time.

So, you're saying you've done this? Are the batteries easy to source? I have a very dead 7b battery collecting dust and I'd love to swap it out if possible.

So, you're saying you've done this? Are the batteries easy to source? I have a very dead 7b battery collecting dust and I'd love to swap it out if possible.

aha can I buy it from you....*wink*yes it's easy to swap out. find the right screwdrivers, then desolder, switch, resolder.the circuit board (or whatever it's called) is quite tightly packed so you need to jiggle it around abit to free it from the casing.The casing is quite tight also so there is abit of flexing of the casing involved once you've unscrewed everything, to remove the battery

Jing - thanks for the info! I pulled a battery apart this morning and have found a source online for replacement batteries for under $60! I've also got an Acute 6b battery that is shot that I'm going to replace.

Now I just need to source the bulbs for the heads jd e11 120v 250w if anybody knows to get them cheaper, they sell after market ones at b&H and are around $7 each and good reviews from profoto users! but the shipping is silly money. It is a cheek paying £19 + vat + delivery for bulbs that cost 3-4 £

My batteries work great, but I'm trying to lighten the load of the 7B. I had heard too that Lithium batteries were now available. Has anyone here actually purchased one and successfully installed it, and is using it? Thanks.

I own the b2 with Lithium batteries - working fantastic. 4-6hours of fashion shooting with no problems - still green led. Compared to my "old batteries" - they were down after this time. Therefore I had 2 batteries - just to be safe for the job on location. I know it´s a high price - but a invest for the future. Now it´s time for Profoto to work on the charger plug in - a nightmare. So loose..

nice to see this thread,here's what I did a couple of months ago.I have a couple of Hensel Porty Premiums with the bigger lead acid batteries.

I am in the UK and sourced the same battery only LI+, very inexpensive compared to buying new lighter ones from Hensel.everything was easy to do and they work fine, my problem however is two fold, hopefully some bright sparks on here can help.firstly I cannot run these new lighter batteries at full power... it just shuts the whole thing down, anything up to one stop below full power and it's fine.

Second niggle is that I cannot run these batteries on the faster recycle mode, again it just shuts them down, it's not a huge problem as they recycle quicker than the older sealed ones.

I suspect that these batteries are maybe not as powerful as they say on the box so to speak, but any thoughts from fellow readers would be welcome.

Stevebri, I'm having the exact same problem with my Profoto b2/7b packs (I'm in the US by the way). I replaced the sealed lead-acid core with a sealed lithium core and the pack will shut down or quickly drain (much quicker than the actual Profoto lithium battery) on the faster recycle time. The higher power doesn't seem to be as much of an issue. I believe the reason to be the protection circuit module installed inside the sealed lithium battery core. A PCM is installed in every sealed lithium battery core and it regulates the battery to keep it from overcharging, undercharging, and producing too much discharge power. After speaker with the battery company (the company I sourced the lithium batteries from) I found out that the PCM installed in the lithium core I purchased only allows a peak discharge current (the amount of current discharging for less than 2 seconds, some batteries it's 5 seconds) of 36A, while the profoto board that the core is wired to has 40A fuses. If the discharge is greater than 36A the PCM will shut the battery down. The faster recycle time and higher power draw much more current than the lower settings, on an AC pack (such as a profoto 7a pack) it can be the difference of 7-8A between the regular and fast settings (or half-power and full-power) leading me to believe that my pack is drawing somewhere between 37A and 40A at these settings and the PCM is shutting it down. I'm contacting the battery company today to see if they can send me a PCM with a peak discharge of 40A to install on the pack. I'm not sure about the power draw on the Hensel packs because I've never used them, but I believe the problem you are running into is caused by the same issue I have. If you can find out let me know what you find, I'd be interested to hear if it was the same situation. I'll update once I get the new PCM installed.